Re: Help Installing a Dual Boot Debian and Mac OS MacBook Pro 9,1

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

Rafael Lauda qrote:
> I have installed the iso image for Debian 8.7.1 1 onto a DVD-R.

How exactly did you do this ?
(What program did you use, which options therein, any peculiarities ?)

>From which URL did you get the ISO ?


> I have installed rEFInd [...]
> When the computer is turned on the dvd does not show.

I understand from
  http://www.rodsbooks.com/refind/using.html
  http://www.rodsbooks.com/refind/features.html
  http://www.rodsbooks.com/refind/configfile.html
that the DVD will show up if there is a file  *.efi  underneath the /EFI
directory of a recognized filesystem.

Well, if it is overly smart by looking into the ISO 9660 filesystem and
not smart enough to follow the El Torito boot catalog entry to the
FAT filesystem in /boot/grub/efi.img, then there is no boot loader
detected.

Suspiciously, the wiki page
  https://wiki.debian.org/MacBook#Installing_rEFInd
describes installation of rEFInd _after_ installing Debian from ISO.


>  I’m not the most tech savvy 

Then be cautious with my next request. Don't do it if in doubt:

Can you put the ISO plainly onto an USB stick and try to boot from
that one ?
See
  https://www.debian.org/CD/faq/#write-usb
  "Please note, that Debian advises not using "unetbootin" for this task."

The danger is that you could use the wrong /dev/sd address and thus
overwrite the wrong disk device.

So get an overview of disks while the USB stick is _not_ connected:

  ls /dev/sd?

and then again when the USB stick is plugged in.
There should appear a further /dev/sd-something name. E.g.: /dev/sdc

Make sure by reading 100 MB from it and checking whether the USB stick
blinks:

  dev=/dev/sdc

  sudo dd if="$dev" bs=1M count=100 of=/dev/null

Only if you are sure to have the right address the ISO to it 

  sudo dd if=debian-8.7.0-amd64-DVD-1.iso of="$dev" bs=4M ; sync

if= path to input file (harmless)
of= path output file (dangerous)
bs= block size (moderately large for best speed)
count= copy size restriction (only in the test read run)


Have a nice day :)

Thomas